In reply to anthonyecc: There is an alternative. The Silva L1 comes with a small battery pack on the head band and a remote pack too for 4 c cells. Unlike the petzl they have voltage regulation so don't slowly dim. the 4 battery's also keeps the long beam (3watt, 60 odd meters) a realistic option. They are available for under £60, not bad considering how bright it is and the two battery packs; very happy with mine, use it for cross country running.
Steve